1. Field of the Invention
This invention is generally related to small land vehicles and, more particularly to recumbent tricycles.
2. Description of Related Art
Recumbent tricycles or trikes are closely related to recumbent bicycles, but have three wheels instead of two. The added wheel eliminates the need for the rider to balance to keep the vehicle upright, almost eliminating the possibility of falling from the vehicle, a major cause of injury with two-wheeled bicycles. A recumbent tricycle is a tricycle that places the rider in a laid-back reclining position and which has a pedal crank in the front area of the tricycle. The reclined, legs-forward position of the rider's body presents a smaller frontal area and delivers an aerodynamic advantage over conventional tricycles. Additionally the rider's weight is distributed over the rider's back and buttocks on a seat that can be shaped for comfort. Recumbent bicycles and means for collapsing vehicle frames have been described in the literature as well as various patents. An example of a recumbent bicycle having adjustable-length frame and adjustable-angle seat is shown in U.S. Pat. No. 5,584,494. An example of a recumbent bicycle having under-seat steering connected by a steering link is shown in U.S. Pat. No. 4,283,070.
Recumbent tricycles are manufactured using the range of manufacturing methods used for bicycles, including frame fabricating materials and methods and the use of the range of standard bicycle components including frame parts, wheels, brakes, gears, pedal cranks and suspension parts. In addition there are further methods and components that are often used on both recumbent tricycles and recumbent bicycles, including seats adjustable in position and angle, chain pulleys and chain sleeves to contain side and vertical movement of the long chain, and an adjustment between the seat and pedals for riders of differing leg length. Examples of recumbent tricycles are shown in U.S. Pat. Nos. 7,354,055; 5,069,469 and 4,548,421.
One type of recumbent tricycle has a seat in front of a rear wheel, a pair of forward steering or front wheels and a pedal crank assembly at the front, and is known as a “tadpole” tricycle. A common type of tadpole tricycle has a spine frame, supported by a rear wheel and a pair of steerable front wheels. A pedal boom extends forwardly of the spine and supports the pedal crank assembly. A drive system connects the crank assembly with the rear wheel. The spine supports the seat. Each front wheel is supported from the spine by a lateral arm having a proximal end and a distal end with the front wheel pivotably attached at the distal end. The frame includes one or more rear support members or “chainstays” supporting the rear wheel. A linkage means maintains the front wheels generally parallel irrespective of orientation and can include a pivoted radius arm having a pivot end and an arc end wherein the arc end connects a pair of tie-rods. The tie-rods are usually of round cross-section with each end having threaded connections providing a means to adjust their length and adjust the front wheels parallel. Methods of recumbent seat angle adjustment include the use of adjustable length stays between pivots at the rear of the seat and pivots on the rear frame portion. An example of this type is the tricycle known as the Terratrike Path, shown in Non-Patent Document 1 (WizWheelz, Mich., USA, Terratrike Owners Manual, February 2008, particularly page 14, item “Adjusting the seat angle recline” and the adjacent image).
A vehicle known as the Challenge Concept Trike has tie-tods of aerofoil shape, which can lose their aerodynamic advantage if not aligned with tricycle travel. This vehicle has lateral arms attached rigidly to the spine and is shown in Non-Patent Document 2 (Velo Vision, United Kingdom, Velo Vision March 2007, pp 12-15, “Three Wheel Challenge”, particularly on page 14 the image “below right” showing the “steering tracking adjustment” on the Challenge Concept tricycle). The radius arm has two arm parts supported from the forward side of the pivot and continuing around the pivot to the arc end at the rear. Each arm part supports a tie-rod connection at the arc end and fasteners between the arm parts allow for fine adjustment in the width of the tie-rod connection points. This adjustment can allow fine adjustment to align the front wheels parallel while the tie-tods remain aligned with tricycle travel.
Tadpole tricycles designed for racing but not intended to be collapsible have a frame geometry that includes lateral arms that are generally normal to the spine in plan, to provide the most strength and rigidity for the least weight. These high performance tricycles have a low seat for efficient aerodynamics and a low centre of gravity to allow high speed cornering. For maximum efficiency, the drive system has a minimum of diversions and of chain pulleys.
Recumbent tricycles are necessarily long and wide to accommodate a reclining rider and they occupy a large amount of space for storage and for transporting in a motor vehicle, bus, train, an aeroplane or the like. They are difficult to fit through gates and other narrow places. This is a long recognized problem and there have been many attempts to design a tadpole tricycle that collapses easily and quickly to a compact form without compromising the performance properties of the tricycle when in use.
One type of collapsible recumbent tricycle is the type having one or more separation points in the frame with fasteners or coupling devices to hold the frame together. An example of this type is the tricycle known as the Greenspeed GTO, shown in Non-Patent Document 3 (Greenspeed, Australia, GTO Packing Instructions (Disc Brake Version), 6 Aug. 2004, particularly item 7). This type can be collapsed by removing parts including the seat from the frame and separating the frame portions. Also, this type can be collapsed to a small size but collapsing or re-assembling this type requires mechanical skill and usually tools, and takes a considerable time. The collapsed form has separated parts, including the seat, that need to be handled separately to transport.
It can be easier to collapse bicycles and tricycles where a hinge is used in the frame instead of a frame separation point. This method is common in folding bicycles and examples of a locking hinge for a folding bicycle are shown in U.S. Pat. Nos. 5,440,948 and 4,911,458.
Another type of collapsible recumbent tricycle is the type which collapses by removing the seat and then, via a hinge in the spine, folding the rear portion of the tricycle over the front portion of the frame. An example of this type is the tricycle known as the Greenspeed GT3, shown in Non-Patent Document 4 (Greenspeed, Australia, GT-series Folding Trike Owner Manual, (undated), particularly on page 2 the image “Tricycle Anatomy” and on page 8 the item “Regular Folding”). Another example of this type of tricycle is the tricycle known as the ICE Vortex, shown in Non-Patent Document 9 (Inspired Cycle Engineering Ltd, UK, ICE 2010 Owner's Manual, 11 Feb. 2010, particularly section 2.2 Folding and Unfolding, pages 4-6).
In the Vortex, the hinge pivot is oriented to place the rear wheel generally horizontal when the rear portion of the tricycle folds over the front portion of the frame. This folding means allows the use of a larger rear wheel while potentially decreasing the tricycle folded height. In all tricycles of this type the hinge opens at the bottom and so the weight of the rider applies a force to open the hinge if the hinge locking devices should ever release while being ridden, a significant problem. The embodiment shown in Non-Patent Document 9 includes an example of under-seat steering wherein the handlebars have provision to be unclamped to be adjusted and the upright handlebar ends folded down to be generally horizontal to allow space for the rear wheel. Collapsing this type produces a still bulky assembly that requires some mechanical skill and considerable time to reassemble the removed parts.
The collapsed tricycle has reduced length but approximately the same width. In some embodiments the main collapsed assembly can be awkwardly rolled on the two front wheels but the width of the tricycle severely limits the usefulness of this function. The collapsed tricycle still requires considerable storage space and the collapsed form has separated parts, including the seat, that need to be handled separately to transport.
As can be appreciated, inwardly retracting the paired wheels of any type of tricycle can significantly reduce the width of a tricycle. Achieving this in an effective and reliable way has been an ongoing pursuit. Examples of various vehicles having pairs of wheels that can retract inwardly are shown in U.S. Pat. Nos. 7,207,407; 7,059,621; 6,742,797; 6,575,486; 5,284,355 and 4,767,130.
Yet another type of collapsible recumbent tricycle is described in U.S. Pat. No. 5,145,196 (Langkamp). This type has stub members having a proximal end and a distal end extending from each side of the spine with pivots at the distal ends supporting the lateral arms. The pivots allow the lateral arms to fold from a travel position, with distal ends spaced from the spine, to stowed positions alongside the spine and the attached wheels to a stowed position. This type can be collapsed by removing the seat, and moving the lateral arms and thereby the attached front wheels to stowed positions. Collapsing this type of tricycle reduces the width but does not reduce the length of the tricycle.
The combined stub members and lateral arms occupy a significant vertical area. This vertical area precludes a low seat height and a low centre of gravity. The drive system diverts under this area and uses multiple chain pulleys. The lateral arms are arrested in the travel position by separate fasteners through clearance holes. Any movement at these fasteners or at the lateral arm pivots is amplified at the distal ends of the lateral arms by approximately the ratio of the lateral arm length to the distance between the pivot and the fastener. This can lead to tricycle steering problems and instability especially when travelling at high speed. This type also includes separate fasteners securing the seat, resulting in a plurality of fasteners on the tricycle and this type can take a considerable time to collapse and re-assemble. The separate pivot assemblies for each folding action also provide no mutual re-enforcement or part sharing for weight reduction. The collapsed tricycle still requires considerable storage space and the collapsed form has separated parts, including the seat, that need to be handled separately to transport.
Yet another type of collapsible recumbent tricycle is known as the JM Recumbents JMX2. This vehicle is shown in Non-Patent Document 5 (JM Recumbents, Mexico, Users Manual—JM X2, [undated], particularly FIG. 3 on page 3) and Non-Patent Document 6 (JM Recumbents, Mexico, Folding Recumbent Trikes, catalogo.pdf, [undated], particularly on page 5 the image of the collapsed frame showing holes on the stub members and on the lateral arms for fasteners to arrest rotation of the lateral arms). This type additionally includes a pivot for folding the boom back and against the spine, means for removing the rear wheel, and a pivot for folding the rear chainstays forward and adjacent the spine when the rear wheel has been removed. The pivot axis is generally horizontal and normal to the spine axis to maintain the rear wheel (if it could remain attached) generally vertical. The lateral arms are oriented forward at a significant angle to the spine normal, resulting in longer lateral arms and deviating from the optimum frame geometry for high performance recumbent tricycles.
Similar to the Langkamp type this type has lateral arm pivots on stub members, and the lateral arms are arrested in the travel position by separate fasteners through clearance holes, and the drive system diverts under the stub members and uses multiple chain pulleys. Any movement at the lateral arm pivots or fasteners, resulting from causes such as clearances or wear, is amplified at the distal ends of the lateral arms and can lead to tricycle steering problems and instability. The longer lateral arms increase any movement at the lateral arm pivots. The tricycle includes separate fasteners for securing the seat and also for arresting boom pivot rotation, the plurality of fasteners making this type slow to collapse and re-assemble the front of the tricycle. The seat must be removed to permit the boom to fold back against the spine. Additionally the separate pivot assemblies for each folding action provide no mutual re-enforcement or part sharing for weight reduction. This type can be reduced to a compact size but collapsing this type takes a considerable time and the collapsed form has separated parts, including the seat, that need to be handled separately to transport.
Yet another type of collapsible recumbent tricycle includes tricycles known as Aiolos Trilite. Embodiments of this type are shown in Non-Patent Document 7 (Aiolos, Germany, Aiolos Trilite pricelist TL.DH 0.9 24″, February 2009, particularly on page 3 the image of one embodiment showing the frame area adjacent to the radius arm including stays between the spine and the lateral arms) and Non-Patent Document 8 (Velo Vision, UK, Velovision Special Needs Buyers Guide, Velo vision Issue 11, September 2003, particularly on the final page, the item “Travel by Trilite” with images of an Aiolos Trilite). This type also includes a pivot for folding the boom back and against the spine, means for removing the rear wheel, and a pivot for folding the rear chainstays forward and adjacent the spine when the rear wheel has been removed. The pivot axis is generally horizontal and normal to the spine axis to maintain the rear wheel (if it could remain attached) generally vertical. It includes lateral arm pivots on stub members but the lateral arm pivots are longer than those in the JM type and provide increased support to the lateral arms compared to that prior type. However the stub members and lateral arm pivots occupy a significant vertical area. This vertical area precludes a low seat height and low centre of gravity. The drive system diverts under this area and uses multiple chain pulleys. This type also includes extra stays between an intermediate portion of the lateral arms and the spine to arrest the lateral arms in the travel position.
In one embodiment of this type (refer Non-Patent Document 7) a fastener on each stay connects that stay to the spine and those fasteners need to be individually removed to stow the lateral arm. In another embodiment of this type (refer Non-Patent Document 8) a fastener connects the stays to the spine and is slideable along the spine to stow the lateral arms. This embodiment includes a radius arm that is also slideable along the spine, allowing the tie-rod length to be accommodated when the lateral arms are stowed. Additionally the tricycle includes separate fasteners for securing the seat and also for arresting the boom pivot, the plurality of fasteners making this type slow to collapse and re-assemble the tricycle. The seat must be removed to permit the boom to fold back against the spine. The separate pivot assemblies for each folding action provide no mutual re-enforcement or part sharing for weight reduction. This type can be reduced to a compact size but collapsing this type takes a considerable time and the collapsed form has separated parts, including the seat, that need to be handled separately to transport. The embodiment of Non-Patent Document 8 includes an example of push-pull (or tractor) steering.
While all the aforementioned recumbent tricycles are variously successful in collapsing a recumbent tricycle to a reduced size they are all deficient with respect to providing a tricycle capable of being quickly collapsed to a compact size and remain whole. Those that can collapse to a compact size all require removal of the seat and the operation or removal of multiple fasteners when collapsing. They thereby require a considerable time to collapse and the collapsing process produces separated parts. Those that can collapse to a compact size by stowing the lateral arms and the boom alongside the spine also make significant compromises to the frame geometry of a performance tricycle. What is needed is a recumbent tricycle that overcomes these problems to provide a tricycle with performance frame geometry and an efficient drive system, and can be collapsed quickly and easily to a compact size, and not require removal of parts from the tricycle.